Ovaries make cysts for a living: When to do no harm

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How to distinguish cysts that require surgery from those that don’t



CASE Should you remove a 6-cm cyst?

Mrs. M, 34, complains of sudden-onset, left lower quadrant pain that woke her from sleep. She has no nausea, vomiting, fever, or abnormal bleeding. Vital signs and temperature are normal. She has a tender left lower quadrant with normal bowel sounds. The pelvic exam reveals a 6-cm tender, but mobile, left adnexal mass, and transvaginal pelvic sonography shows a 6.3-cm cystic mass with a thick septation and some internal echoes. Is surgery necessary?

Few cysts present with sudden pain unless they are undergoing torsion, are hemorrhagic, or are in the process of rupturing. Therefore, in the case of Mrs. M, these benign conditions should be considered first. Cancer is very unlikely to be the cause of sudden pain.

A common phenomenon, and usually benign

How widespread are ovarian cysts? About 8% of asymptomatic women between the ages of 25 and 40 have ovarian cysts larger than 2.5 cm.1 A study of women 50 or older found unilocular cysts smaller than 10 cm in 18% of cases.2 Although many cysts resolve spontaneously, some women may be subjected to unnecessary surgery because of concerns about ovarian cancer. In actuality, various studies have shown that cysts found prior to menopause are benign in 87% to 93% of women, and cysts found after menopause are benign in 55% to 92% of cases.3 The gynecologist’s dilemma is to differentiate between cysts that require surgery and those that do not.

This article details the careful assessment that should guide this important decision.

Detorsion of the twisted ovary restores function

In addition, when torsion is present, rather than resort to removal of the adnexa, simply untwist it, even if the tissue does not appear to be viable. Studies have shown that this maneuver leads to a return of ovarian function, as evidenced by follicle formation on subsequent sonograms. In addition, no case of thromboembolism has ever been reported following detorsion of an adnexa.4

Physical clues to the type of cyst

The pelvic examination can yield important clues. For example, a mass that is compressible, smooth, and freely mobile is likely to be benign.

As already noted, tenderness is more common with a hemorrhagic cyst or with torsion, and is rarely associated with cancer. A solid, fixed, irregular mass, however, should raise the suspicion of cancer.

If ascites or an abdominal mass is found, assume the patient has cancer until proven otherwise.

Sonographic appearance

If you do not perform the sonogram yourself, it is a good idea to view the actual images. The reason: Many radiologists use the term “complex” to describe all cysts other than totally clear, simple cysts (FIGURE 1). However, many benign entities are complex, such as dermoid cysts, endometriomas, hemorrhagic cysts (FIGURE 2), and cystadenomas. Careful scrutiny of the images and, at times, other imaging studies, can help determine the most likely diagnosis.

Dermoid cysts can often be confirmed by limited computed tomography scan when fat (sebaceous material), teeth, or bone are seen within the ovary.

Torsion may be suspected when Doppler imaging shows decreased or absent blood flow to the ovary.

A small amount of free fluid in the pelvis is an indication of possible cyst rupture.

If a hemorrhagic cyst is present, a follow-up sonogram about 2 weeks later may show either a smaller cyst or changes in the internal echoes consistent with an organizing clot (FIGURE 2).

False-positive CA 125 rate in young women: 70%

Markers such as CA 125 are rarely helpful in determining how to manage a cyst in a young woman and should be avoided in the premenopausal population. Abnormally high CA-125 values can occur with endometriosis, functional cysts, fibroids or adenomyosis, pelvic infection, pregnancy, and cyclic elevations associated with the menses.

In a premenopausal woman, the chance of a false-positive CA-125 reading is about 70%,5 whereas 50% of women with stage I ovarian cancer have a negative test.6

2 useful markers

Very young women are at risk for developing germ-cell tumors, which may produce β human chorionic gonadotropin or alpha fetoprotein. Thus, these tumor markers are sometimes helpful in this patient population.


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